cdoug, we work in the same state, so my first advice to you is to learn the BJ mechanics in Maurer's "Gold Book." That's going to be the standard for judging mechanics in Ohio. The 2011 manual came with your state packet, but the 2010 version is also here:
http://ohsaa.org/sports/ft/boys/2010...Manual2010.pdf
So, for example, many people will tell you that you should start backwards at the snap: that is NOT an approved mechanic in Ohio. On short passes and runs up the middle you read your keys and stay up.
Still, you don't want to get beat deep. After you read pass, check the QB: if he's looking to the side with a receiver going deep, then get going. Don't get beat deep.
You've got the 25 second clock: don't forget to raise your hand with 5 seconds to go. In my games, that clock is really more like 28 seconds, unless the game is decided or the team with the lead is trying to run out the clock.
If you're covering your primary, you won't throw many flags. That's fine. Be a great dead-ball official: you have the broadest view of the field after the play. You should be part of the "triangle" getting the ball spotted on plays of 10+ yards (R takes it on shorter plays), but keep your eyes open.
Like all the positions, there's a rhythm to BJ. Relax and try to find it. RFP, start your clock, count B, read A's formation, keys, QB, play, cleanup, spot the ball.
Oh yeah, and have fun! You've got the best view of the game!